Most electronic apparatuses have exhaust fans for ventilating their power supply units. That is the case with a projection type image display apparatus, such as a liquid crystal projector, that includes a high-luminescence light source such as a high-pressure mercury lamp, which operates at a high temperature. Since the air in the light source unit can be heated to a higher temperature than that in the power supply unit, a measure is taken to ventilate the light source unit. For example, the blast power (or rotational speed) of the exhaust fan is raised to the maximum level, or a larger exhaust fan is employed, or multiple exhaust fans are provided.
Japanese Patent Application Laid Open No. 2000-19644 discloses an image display apparatus equipped with two adjoining exhaust fans, installed near the light source unit, for ventilating its light source unit and power supply unit.